Generic Index

DIGOXIN ( di-JOX-in )

Rapid digitalization with a loading dose: 400 to 600 mcg (0.4 to 0.6 mg) IV 500 to 750 mcg (0.5 to 0.75 mg) PO as a single dose; additional doses of 100 to 300 mcg (0.1 to 0.3 mg) or 125 to 375 mcg (0.125 to 0.375 mg) PO may be given cautiously at 6- to 8-h intervals until clinical evidence of an adequate effect is noted.

Consider the differences in bioavailability between digoxin injection, tablets, and oral solution when changing patients from one dosage form to another. See Pharmacokinetics.

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For IV administration, digoxin injection may be diluted (4-fold or more) with normal saline, dextrose 5% in water, or sterile water for injection. Infuse slowly, 5 min or longer.

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IM injection can lead to severe pain at the injection site. If the drug must be administered IM, inject it deeply into the muscle and follow with massage. Do not inject more than 2 mL into a single site.

OB: Pregnancy (although safety has not been established, has been used during pregnancy without adverse effects on the fetus);Lactation: Similar concentrations in serum and breast milk result in subtherapeutic levels in infant, use with caution).

Digoxin serum concentrations may be elevated, increasing the pharmacologic effects and risk of adverse reactions and toxicity. Observe the clinical response of the patient and monitor digoxin serum concentrations. Adjust the digoxin dose as needed.

May decrease digoxin absorption, decreasing the efficacy. Administer digoxin at least 2 hours before the aluminum salt. Separate the administration times of digoxin and cholestyramine or colestipol by as much as possible. Separate the administration times of digoxin and sucralfate by at least 2 hours.

Amiloride, spironolactone

The positive inotropic effect of digoxin may be attenuated. If an interaction is suspected, discontinue one or both drugs. In addition, spironolactone may interfere with digoxin assay, resulting in falsely elevated levels.

Aminoglycosides, hydantoins (eg, phenytoin)

Digoxin pharmacologic effects may be increased or decreased. Observe the clinical response of the patient and monitor digoxin serum concentrations. Adjust the digoxin dose as needed.

May increase digoxin absorption because of a decrease in GI motility. This interaction may be specific to the oral digoxin preparation and may be greater with slower dissolving tablets compared with digoxin elixir, or more recent tablet formulations.

Dofetilide

Coadministration of digoxin and dofetilide has been associated with an increased rate of torsades de pointes.